Backfiring/Missing GQ

Submitted: Tuesday, Feb 01, 2005 at 14:49
ThreadID: 20011 Views:2027 Replies:8 FollowUps:2
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Hi all, thanks for replys on previous posts, when I have a spare $50 I will join up. mY 89 GQ has been backfiring and missing for sevearl months. I have tried changes, one thing at a time, but there doesnt seem to be any thing that makes it better for more than a few weeks. I have tried, fuel filter, fuel pump, spark plugs, leads, coil lead, metho in the fuel tank (water?), dizzy cap, points, rotor. Its driving me crazy. Whilst the spark plugs have improved fuel efficiency, and it doesnt back fire as much, it has a really annoying miss. The only way to describe it is that it breaks down, usually up hill, and often when adjusting speed from coasting and then slightly accelerating at 100ks/hr for instance. Usually not a problem when cold, more often when at running temp. The needle on the taco goes mental. it doesnt last more than a few seconds.
Could it be float, coil what do I do next. ihave had the timing adjusted and checked by two reputable(?) mechanics in Perth and basically just got short changed with no improvement or suggestions.
What do you guys think?
Happy Trails
Hano
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Reply By: Truckster (Vic) - Tuesday, Feb 01, 2005 at 14:54

Tuesday, Feb 01, 2005 at 14:54
Have you rebuit the carby?
AnswerID: 96046

Reply By: Alan S (WA) - Tuesday, Feb 01, 2005 at 15:00

Tuesday, Feb 01, 2005 at 15:00
Hano

Have you checked or replaced all vacuum hoses?
AnswerID: 96048

Reply By: Tony N. (VIC) - Tuesday, Feb 01, 2005 at 15:06

Tuesday, Feb 01, 2005 at 15:06
Had a simular problem with a 55 series L/C.

It would backfire at varing times and the tacho would go nuts.

Worked out it was a faulty Electronic ignition (after market), I had breakerless ignition and I had upgraded the coil to a Bosch GT40R and it killed the ignition unit.

The other thing that could be causing your problem is the condensor that is in the distributer, it could be breaking down and causing a false spark.

Hope this helps.

Tony N.
AnswerID: 96049

Follow Up By: G.T. - Tuesday, Feb 01, 2005 at 17:50

Tuesday, Feb 01, 2005 at 17:50
Spot on! I chased an intermittent miss fire until I replaced the condensor. Problem solved ! regards G.T.
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FollowupID: 354857

Reply By: Chucky - Tuesday, Feb 01, 2005 at 18:00

Tuesday, Feb 01, 2005 at 18:00
I would check that all your electrical connections are good on the ingnition system. From what you say it sounds like a short somewhere that is causing power loss in the electrical system.
AnswerID: 96087

Reply By: muzzimbidgie - Tuesday, Feb 01, 2005 at 18:56

Tuesday, Feb 01, 2005 at 18:56
I had a similar problem with a 60 series cruiser.

Ended up being a stuffed shaft inside the distributor. The only way the mechanic found it, after months of fualt finding missions, was to remove the distributor from the side of the engine and check for freeplay in the the shaft.
AnswerID: 96104

Reply By: GOB & denny vic member - Tuesday, Feb 01, 2005 at 19:02

Tuesday, Feb 01, 2005 at 19:02
as a former owner witha similar problem get an extended rotor it will cure your problem straight away
you can order over the phone from lpg 1 in lilydale melb

steve
AnswerID: 96106

Reply By: Member - 'Lucy' - Tuesday, Feb 01, 2005 at 19:04

Tuesday, Feb 01, 2005 at 19:04
Evening Hano

I have a friend who had a ford escort some years ago which was doing exactly the same.

We finally pegged it down to the condensor in the 'dizzy'.

B A S T A R D of a thing was alright when cold/warm, however as soon as it got hot, hell it had a mind of its own.

The temperature aspect may be a hint to what it is in your case.

New condensor returned it to normal.

Regards

Ken Robinson
AnswerID: 96107

Follow Up By: Hano - Tuesday, Feb 01, 2005 at 19:13

Tuesday, Feb 01, 2005 at 19:13
Looks like I have a direction to follow, thanks Fellas, off to the shops for a condensor first, then see what happens....
Hano
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FollowupID: 354871

Reply By: stephenjNQ - Wednesday, Feb 02, 2005 at 15:02

Wednesday, Feb 02, 2005 at 15:02
hano , GOB has the answer, my maverick was doing the same , replaced everything from plugs , cap ,lead ,coil and rotor button. still not fixed ,put extended rotor problem gone. regards stephenjNQ
AnswerID: 96256

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